Climate Science Glossary

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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Misleading 'Pause' Articles

However, over the past week or two there has been a spate of articles from the New York Times, Washington Post, The New Republic, and Der Spiegel, all of which get many details right (including noting the warming of the oceans), but that all begin from the premise that “global warming” has slowed.

It would be more accurate to say that global surface air warming has slowed, but the overall warming of the Earth’s climate has sped up. Only about 2% of the planet’s overall warming heats the atmosphere, so if we focus only on surface air temperatures, we miss 98% of the overall warming of the globe.

Figure 2: A visual depiction of how much global warming heat is going into the various components of the climate system for the period 1993 to 2003, calculated from IPCC AR4 5.2.2.3. Note that focusing on surface air temperatures misses more than 90% of the overall warming of the planet.

What is 'Global Warming'?

About 90% of the warming of the planet is absorbed in heating the oceans. However, until the past few years, our measurements of ocean temperatures (especially of the deep oceans) were somewhat lacking. Our measurements of surface air temperatures were much more accurate, and so when people spoke of “global warming,” they tended to focus on air temperatures.

In the 1980s and 1990s when air temperatures were warming in step with the overall warming of the planet, that was fine. However, over the past decade, the warming of surface air temperatures has slowed. At the same time, the overall warming of the planet has continued, and if anything it has accelerated. This has been difficult to reconcile for those who previously focused on surface air temperatures – what do we say about “global warming” now?

The result has been the series of articles linked above, which begin from the premise that global warming has "stalled." However, given that the overall warming or heating of the planet continues at a rate equivalent to 4 Hiroshima atomic bomb detonations per second, this framing of the issue is clearly inaccurate and misleading. The articles did subsequently discuss ocean warming, but the initial framing of the supposed 'global warming pause' is bound to confuse readers.

What's the Deal with Slowed Surface Air Warming?

Research on the causes of slowed surface air warming is of course ongoing. The question remains how much other factors have contributed to the surface warming slowdown. For example, aerosols and low solar activity over the past decade likely played a role as well. However, Watanabe et al. (2013) suggests that these factors can’t explain most of the slowed surface warming, which his study attributes to a more efficient transfer of heat to the deep oceans. This result is consistent with the 'hiatus decades' found in Meehl et al. (2011) and (2013).

The Naive Economist Blog

The bottom line is that the body of scientific research suggests that the current slowed surface warming is mainly due to natural oceanic cycles, and thus is only a temporary effect. However, a political blog for the Economist suggested that we should take a 'wait and see' approach for 'a decade or two'.

The argument is based on both the surface warming 'pause' and the premise of low climate sensitivity. However, research has remained consistent with the IPCC range of 2–4.5°C equilibrium warming in response to a doubling of atmospheric CO2. Some recent research has suggested the value might be toward the low end, but other recent research has suggested otherwise. In any case, even in a realistic best case scenario, we're not doing enough to decarbonize the economy if we want to avoid dangerous and potentially catastrophic global warming.

Taking a ‘wait and see’ approach for another decade or two would be a recipe for certain disaster. Fortunately that blog recommendation is at odds with the approach suggested by The Economist’s correspondents, who agree that in any case we’re not doing nearly enough to decarbonize the economy if we want to avoid dangerous climate change.

We Need to Hit the Global Warming Pause Button

The key take-home point is that we now have better measurements of ocean and global heat accumulation. We no longer have to settle for focusing on the 2% of global warming represented by surface air temperatures. Consider the analogy offered by Greg Laden, that the planet is a dog and surface temperatures are his tail. In the past we only had a GPS locator on his tail. It wags around a lot, sometimes accurately representing the movement of the dog, sometimes not. Now we’ve got a second GPS locator on his body – should we continue focusing on the movement of the tail for old times’ sake, or should we shift our focus to the more representative measurements?

Ideally people will begin using the term “global warming” to refer to the planet’s overall heat accumulation. Or use the term “global heating” or “climate change” or “global disruption.” Whatever term is chosen, we need to stop misleading people by saying that global warming has “paused.” The overall warming of the planet has not and will not pause until we stop increasing the greenhouse effect through our reliance on fossil fuels. The warming will only continue to grow.

Comments

Answering James Madison from another thread. James, you appear to claiming that observed temperature rise is not in keeping with the model predictions. The reason I asked what was your model, was because it appears your broad model assumes linear increase in CO2 means near linear increase in surface temperature. In fact, if you look at an individual GCM run, (not ensemble mean), then no such prediction is made. To me, it seems you are attacking predictions that were never made. That might indeed be a problem with communicating science, but it is not a problem with the science. Surface temperatures have a very large component of internal variability. This is well known and reasonably well understood. That is the reason why I pointed you to total OHC - a better diagnostic as temperature imbalance.

If you think global warming is outside predictions, perhaps you would note that we have had a long string of La Nina/neutral phase in ENSO. This strongly influences surface temperatures. Care to make a prediction on what the surface temperature will do when the next 1.8 or higher El Nino occurs or do you think such an event wont happen again. (you can find an historical record of ENSO here).

scaddenp... You know, that's really interesting you mention this. I think you've exactly nailed one major misinterpretation of climate models. I've tried to explain the same thing numerous times in the comments sections of many climate articles.

Some people seem to believe that the mean is what surface temps are "supposed" to do; or are project to do. And it's nothing of the sort.

I often tell them that the ensemble range sets the boundary conditions for what we expect to see, and right now we are at the low end of those boundary conditions. But we are clearly still within those boundary conditions, thus the models are still currently correct.

If we continued with 10 more years of slow or no warming, then something is amiss. I don't expect that is what will happen. It's more likely that we are going to see another rapid rise in surface temps over the coming couple of decades.

Speaking of climate change, Phil Plait made some excellent points in a recent post on his Bad Astromony blog.

The melt in Greenland and the high temperatures in Alaska may be more signs—like we needed more—of the reality of climate change. Even scarier is the fact that the climate models used before didn’t predict this sort of thing. The climate is very complex, and it’s hard to model it accurately. This is well-known and is why it’s so hard to make long-term predictions.

But before the deniers crow that climatologists don’t know what they’re doing, note this well: The predictions made using these models almost always seem to underestimate the effects of climate change. That’s true in this case, too. So it’s not that the models are wrong and therefore climate change doesn’t exist. It’s that the models aren’t perfect, and it’s looking like things are worse than we thought.

Even if global warming is the greatest threat to humanity since the Bubonic Plague, asking governments to address the problem with legislation is like putting Homer Simpson in charge of guarding the beer keg. D'oh! Whatever the U.S. congress does to address the problem is 100 percent certain to make matters worse. The reason I'm a skeptic is because I see and hear intelligent climate scientist calling for a political solution, and that is just plain nuts.

Ned - I find this very hard to comprehend. You are skeptical about published science because people are asking for something to be done? Because studies to date show that mitigating will be way cheaper than adaptation? This makes no sense at all. Let me put another example. Suppose science instead finds that there is asteroid on collision path with earth with 99% probability and also put up a number of potential avenues by which this might be averted. Are you going to be skeptical that the asteroid exists because they are funnily enough jumping up and down and asking for something to be done about it? What should they do?

This sounds very much like this little piece of logic:

"If AGW is true, then it is better to mitigate. I dont like proposals for mitigation, ergo AGW cant be true."

Is that really what you mean? On the other hand, solutions to date have had a lot of trouble gaining traction, particularly with with political right. Perhaps you would like to take the challenge here and say what you think should be done if you were convinced AGW needed mitigation.

I'm not very happy with this (kind of) "liberal" approach on terms. When that what has been measured and shown by the scientific community throughout ages is "global warming" - then by all means call it so. The term "climate change" smells like "denier spirit" - just to come by with this usual "well hey, that's ok - climate will always change". Using the wrong term for the noted phenomenon will get us nowhere.

Ned - you don't think humanity has the intelligence to foresee the consequences of our actions, sufficient ethics to act like it matters or the collective organisation capable of incorporating scientific foresight into effective government policies and regulations? You seem to be saying that even knowing that climate change makes bubonic plague seem inconsequential you think no government level efforts should even be attempted due to certainty of failure.

Just this morning, one of Norway's major newpapers, Finansavisen, ran an editorial perpetuating the very same myths.

No surprise, though. Norway has more outspoken deniers per capita than any other nation on earth. Humlum and Giæver are just two of many.

NRK (Norway's BBC) has a bad habit of inviting denialists, but no climate scientists when debating global warming. A well informed denier knows the talking points and will run over a representative from the Green Party andy day of the week.

This is just one tool in the state owned TV Channels quest to form public opinion and gather support for continued explotation of FF reserves in the North Sea and Arctic, securing continuation of major cash flow for the state owned oil company.

The funny thing is that when we hit a new record in the surface temps in 2010, the deniers make a lot of noise that the surface measurements only represented a tiny 2% of the whole system. How things change. I will bet that once the next Nino hits and we get a new surface record, it will be back to the same tune.

Just like Arctic sea ice. If 2013 does not go lower than 2012, they will scream recovery and coming ice age, but when 2014 or 2015 smashes the 2012 record, they will claim that it is all natural and they knew it would happen all along. Denial is easy when you can make up your own facts and reality, and the press never questions it, but call upon you as an expert on the topic.

shoyemore@8 - MT's idea to drop "global warming" is a good one. He's incorrect, however, that Holdren coined the term "climate disruption" - it's been in use since well beore Holdren came along, and I started using it at S&R before Holdren started working for President Obama. That said, however, Holdren did popularize "climate disruption."

Actually, I prefer 'global warming' to 'climate change' or 'climate disruption'. It is more precise in that it explains the primary underlying shift. Yes, the climate is changing and being disrupted... because the planet is getting warmer. Leaving out that the issue is warming would be like having a daily weather report stating, 'big weather changes tomorrow - be prepared!'. Prepared for what, exactly?

How do we prove that 'climate change' hasn't stopped? By showing that warming has continued.

Yes, the simple term 'global warming' doesn't convey all the complexities of what can happen as that warming causes air and ocean currents to shift, but climate change/disruption provides even less information.

I agree with CBDunkerson regarding terms. "Global warming" is the best term for the current human-caused climate change because it is the main characteristic feature of the change.

I would use the term "climate disruption" for relatively short-term deviations from the long-term climate. Major volcanic eruptions typically cause a climate disruption lasting for several years. Other singular events might cause a climate disruption lasting for several decades or centuries (Medieval Warm Period, Little Ice Age, Younger Dryas).

Imagining a miracle, I would call what happened a human-caused climate disruption if we quickly stopped burning fossil fuels and reduced greenhouse gases to something close to the pre-industrial concentrations, resulting in a reversal of the warming and a return to a congenial climate over the next century.

Whenever I talk about Global Warming, I generally try to stress that "Global Warming" and "Climate Change" describe different parts of an overall effect that we tend to lump together. So, while it may be a mouthful, I'll use phrases like "Climate Change as a result of human-caused Global Warming."

No matter what, I'm also hesitant to use "Climate Change" more frequently than "Global Warming." Global Warming is an effect much closer to the source: our GHG emissions. Climate Change is simply the response to that and, to me, it's so far down the line that it doesn't "click" for people.

As for other terms (climate disruption), I think they're even further down the wrong path. The ideas they convey have only very minor differences, and they do nothing but lead people to believe the myth that the nomenclature is some sort of worldwide scientific conspiracy because one or more of the words is "no longer happening."

The only improvement over "Global Warming" (or, better yet, the incredibly wordy phrase I like to use) that I could think of would perhaps be "Global Heating," simply because it stresses energy rather than temperature changes. But that's getting pretty pedantic, and not really worth it in my opinion.

Let me guess.You are referring to the climate "realist" Ole Henrik Ellestad in the program Debatten that aired on June 6th. I didn’t even bother to watch the whole program because I was almost certain about the result, and I was right.

Ellestad got a chance to deliver his "climate’s changed before" and "CO2 lags temperature" arguments and nobody present were qualified or got the chance to argue against him.

I wonder when NRK will actually let a real climate scientist thoroughly and without interruptions debunk some of the specific arguments that the deniers are promoting. It hasn’t happened yet.

I think AGW is the best title as it states clearly that the globe may warm from mans actions, climate change is not a very good title because the climate changes all the time with or without us. Climate extremes, well we already have that think the poles winter/summer etc.

You raise some interesting points re Arctic ice however you need to be careful with what you say. For example Professor Wieslaw Maslowski made a rather bold prediction when he stated according to his model the Arctic will be ice free by the summer of 2013 (see link below)

http://news.bbc.co.uk/2/hi/7139797.stm

Now if we look at the current state of Arctic sea ice we can see it is a long way from being ice free, granted we are a few months away from "peak melt" but the Arctic will not be ice free (see link below)

http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

Obviously Professor Wieslaw Maslowski got his prediction/projection wrong i will be interested in hearing what his reasonings are.

@Donthaveone : you do know that Maslowski's prediction was 2016 +/- 3 years don't you? What is your reasoning for thinking such a prediction would be falsified in 2013, when the uncertainty bound is in the range 2013-2019? Do you think the prediction is unreasonable, given the acceleration in ice volume loss?And yes, climate scientists know full well that climate's changed before (#20). Evidence of that is one of the powerful reasons we know that the Earth is sensitive to change in forcing, including changing CO2 levels- approximately 3C per doubling from palaeoclimate data. For me, global warming is what is happening, climate change and climate disruption are the consequences of our increasing the heat content of the Earth system.

The year 2013 was mentioned numerous times however that was not the point i was trying to make. Esop (14) claimed that "deniers" would use 2013 as evidence of a recovery plus coming ice age etc (if in fact the ice loss ends up less than 2012). Esop then made the unsubstantiated claim that 2014/15 will be lower than 2012 and the "deniers" would then claim this is all part of a natural cycle.

I supplied the link to show that even "experts" can get things wrong and to subtly show Esop that the way they where behaving was the same as those they mock. The artcile i link to clearly states Professor Wieslaw Maslowski claims the the Arctic "could" be ice free in the next 5 - 6 years (from 2007) no mention of a 6 year tolerance. Do you have a link to support the =/- 3 years?

This is the problem with the subject of AGW there are a lot of claims made based on computer models which generally dont pan out but yet according to Esop it is only the deniers that shift the goal posts.

Cheers

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Moderator Response:

[DB] You illustrate the fallacy of relying on news articles instead of primary sources.

In reality, Maslowski's prediction, based on a proprietary model he runs on a US Navy supercomputer at the US Navy Postgraduate School, is 2016 ± 3 years. He originally made this prediction, based on data through the 2005 melt season, in May of 2006.

Maslowski formalized that prediction in January of 2007, here. Maslowski provides more details on his model, and the future of the Arctic sea ice, here.

To sum: you are very much incorrect. In this forum, credibility comes from referencing reputable sources, preferably the primary literature published in reputable journals. Continuing on in the approach you have taken will get you nowhere, here.

Lastly, posts at SkS have a narrow focus. Your reference to models is an unsupported assertion and indicates an unfamiliarity with models. Please read the Models Are Unreliable rebuttal in its entirety before commenting further on them.

Dana, I think you are pushing in the right direction with this; heat content is a much more direct measure of the underlying changes to the climate system than average air temperatures and climate science communicators should make heat content their first response to the suggestion that global warming is something that waxes and (allegedly, recently) wanes.

I think examining the scientific consensus and other efforts by contributors at this site all help. The Escalator is great. Foster and Rahmstorf style adjusted temperatures, that look at the known natural influences help.

I don't know where the best value for effort in communicating the seriousness and urgency of the climate problem lies but one thing that I would like to see is National Academies and the like increasing their role. Not that they've failed to step up, but the idea that they could (again) provide an independent assessment of the science comes to mind. It needs to be done with maximum publicity and video documentation (prime time Television in mind), demonstrating how they select the experts for the right combination of knowhow, independence and integrity. Not that I'm criticising what everyone has done to date but clearly the message is still not being communicated well enough in the face of ongoing, organised, deliberate and well communicated dis- and mis- information.

The assertion is that the ocean will sink excess heat, thus preventing the SST from reaching the same temperature as the land. Over time, we can look at that gap vary. Right now, the gap appears to be widening, thus leading to a leveling of the global temperature.

"global warming" is the best traditional description. "ecosystem warming" would have been better but it's too late now. Would have been far better to have explained what it was from the outset and hoped that enough persons had the ability to understand it, but I suppose it was handy to show surface temperature graphs because of proxies for it going back millions of years. "climate change" is a symptom of "global warming". Surface temperature change is a symptom of "global warming" and is a fever trying to stop it. It's counter-intuitive to hypothesize that, say for example only, AST going quite flat then dropping for a while indicates "global warming" increasing simultaneous with the AST dropping (oceans take heat suddenly in my example, AST drops, TOA radiative imbalance increases). I'm not projecting that (I don't know ocean currents), I'm suggesting if this type of physical possibility had been explained to anybody with a half-decent high school education they'd have found it fascinating.

Me @ 28. Correction: "ecosystem warming" is not correct at all, stick with "global warming", just tell people the heat content of the various major segments of the "global", lakes, oceans, water everywhere.

Ned @ #4 (belongs really on Obama post but yours is here). It's my understanding that U.S. real action is needed to spur China & other industrializing powers by example and moral superiority as the basis for whatever cajoling. Apparently, U.S. & China now ~6 bt CO2 each but China is the rapid increaser (not sure whether that's coal only). So U.S. action is about much more than U.S. CO2 emissions due to their still somewhat pre-eminent position.

It is useful to keep in mind that the net radiative imbalance due to GHG for the entire earth integrated for a year is about the same (6e21J) as the amount of heat absorbed to seasonally melt 20,000 cubic Km of ice that melts annually in the Arctic sea. The same amount of heat is released during refreeze. The amount of heat required to melt enuf ice corresponding to a 1mm rise in sea level is 1e20J.

The amount of heat increase below 2000m is not negligible. I have added to my comments on Balmaseda(2013) with inclusion of estimates from Kouketsu(doi:10.1029/2010JC006464, 2011, 5% OHC increase below 3000m) and Purkey(doi: 10.1175/JCLI-D-12-00834.1, 2013, 14% OHC increase below 2000m south of 30S ) for depths below 2000m.

Sidd @ #30 But the OHC graphs at your link show a slope of 13.2e21J per year from 1990 to 2008 plus you have an extra bit at greater depth (I suppose ~14e21J total). Am I misunderstanding something about these numbers or is your 6e21J per year more historical (like me) ?

DB@reply at 23. You list 3 references for Mazlowski saying 2016± 3. I don't think the first one May of 2006. says that. Page 6 of the slides shows a much less specific statement and I cannot find any further discussion. The other two references do list the figure.

I can't believe I am saying this, as the media covergae of climate change is almost universally appalling BUT I think part of the problem is that we, as the scientific community allowed the message/meme to permeate that media that "warming" was purely an atmospheric temperature phenomena to be assessed solely by average global temperatures.

Some people have trouble counting, a very large number don't really understand what an average is, how to calculate it or what it actually represents. As for a moving average to be messured on, say, a decadal basis - forget it.

And I don't think we scientists have communicated that very well - which is why in part so many still continue to think warming has "paused".

Of course the media has not helped and I do not offer this comment as exculpatory for the media.

But we really need to get better at explaining what "warming" means.

I'm a phsycist - and I remember being highly skeptical about AGW when I first heard about it in the late 80's - reasoning that the ocean was such an enormous heat sink that any impact on atmospheric temperatures would be dwarfed by the impact on increased heat content in the ocean. Well, I was a little bit right.

As I studied the evidence it became clear to me that the issue was real, and that as greenhouse gas levels increased we would see ice mass disappearing and ocean heat content increasing before temperatures rose dramatically.

Yet there was very little of this sort of dialogue in the media. NOR did it feature prominently in the messages given by science.

Now that we know much more than we did about ocean circulation patterns, intermixing and the like (although there is still much to learn) we need to get this message across in much simpler fashion than we have done so far.

For example - this video http://www.colorado.edu/news/multimedia/grace-mission-measures-global-ice-mass-changes could do with more prominence but where is the place one can point to that shows GLOBAL ice mass loss. The best on this site is here (I think) http://www.skepticalscience.com/melting-ice-global-warming.htm - but it's not "simple" enough. We have to reduce the message down to what can be grasped and absorbed quickly. By all means show the detail once we have people's attention but what needs to be understood is the total ice mass loss. because most people can grasp that ice doesn't melt without an injection of heat.

The same with heat content in the ocean. The 90% statistic and the 3-4 hiroshima bombs per second doesn't work - because most people haven't a clue what that means.

We need to translate that into a simple measure - like what would happen if all that excess heat going into the ocean DID get transferred to the atnosphere. Has anyone seen any attempts to produce such a figure?

Or perhaps a thought experiment.

Ask people what they think would happen if we had a large room where 10% of the floor was covered with a large block of ice and a further 70% was occupied by a large tank of deep water at an average temperature of just a few degrees celcius. Assume that the mass of water vapour in the room is about 0.001% of the water in the tank and the ice cube. Further that the total mass of the ice block is about 2% of the mass of water in the tank

We then introduce a modest increase in infrared radiation into the room - at just (let's keep it simple) a uniform 1 Watt/m2.

Where we would notice the effects first? In an increase in ambient room temperature? The ice starting to melt? Or the water starting to gain "heat"?

Or more accurately - where would the (majority) of the heat (energy transfer) go?

Okay, let's assume we must act now as the President expects all Americans to do. Apple announced today it is putting a 43,500 kwhr (~20 MW unit) generating solar plant in Reno, NV. It is equivalent to the carbon generation of some 17,000+ homes. The capital cost will be ~ $75M based on costs of similar sized plants. In order to replace coal, which generates 1,517,000,000,000 kwhr, with solar, we would need some 35,000 such Apple size plants if the entire US had the sunlight of NV which it doesn't. Adjusting for many cloudy regions, we would need more like 70,000 such plants. The total investement would be over $5.0 trillion and in many regions there simply isn't enough space to put solar panels. How would we fund this?

As to cost, Apple hasn't released figures, but it's estimated to be similar to the cost of its other data centers - all of which are powered from renewable energy sources, and none of which has bankrupted the quite profitable company.

As KR mentioned, space for solar isn't a problem. Using an existing parabolic trough system like Nevada Solar One as a benchmark (134 GWh/year, 1.6km2) you could generate the entire planet’s current annual energy consumption (not just electricity) using just 17% of the Sahara desert.

Consider also the fact that we have already disturbed, by coal mining, an area (~8.4 million acres in the US alone) equal to that required to provide all power using solar thermal, and that coal mining has a much bigger impact on the area affected than simply putting it in the shade, and that coal also usually happens to be located in much higher-value areas than solar thermal plants would be.

Solar PV is even less of an issue, because it can sit on existing rooftops, and it has the advantage that it's competing with the end-user retail price of electricity.

If you're worried about cost, however, then you should be comparing to wind, rather than solar. Wind is now cheaper than new coal, which is why it's had such a dominant position in terms of new installed capacity for a while now. (Going forward, you can see the EIA's current estimates for 2018 here. Note that those figures are excluding "targeted tax credits such as the production or investment tax credit available for some technologies".) Wind can also co-exist with other uses of the land (most wind farms I've seen have been on working farms running sheep and cattle).

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